package com.heima.gateway.filter;

import com.alibaba.fastjson.JSON;
import com.heima.gateway.utils.AppJwtUtil;
import io.jsonwebtoken.Claims;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Controller;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Controller
@Slf4j
@Order(0)
public class AuthorizeFilter implements GlobalFilter {
    private static List<String> urlList = new ArrayList<>();
    // 初始化白名单 url路径
    static {
        urlList.add("/login/in");
        urlList.add("/v2/api-docs");
    }
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //获取请求头
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        //判断用户的请求头是否需要拦截
        String path = request.getURI().getPath();
        for (String s : urlList) {
            if (path.contains(s)){
                return chain.filter(exchange);
            }
        }
        //获取请求头中的token信息
        String token = request.getHeaders().getFirst("token");
        if (StringUtils.isBlank(token)){
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();
        }
        //解析token信息
        try {
            Claims claimsBody = AppJwtUtil.getClaimsBody(token);
            int i = AppJwtUtil.verifyToken(claimsBody);
            if (i < 1) {
                //解析成功,获取token中的用户id,将用户id重新设置到请求头中,放行请求
                Object id = claimsBody.get("id");
                //改变request本身的值
                request.mutate().header("userId", String.valueOf(id));
                //改变exchange本身的值
                exchange.mutate().request(request);
                log.info("解析成功,当前登录用户id为:{}",id);
                return chain.filter(exchange);
            }
        }catch (Exception e){
            log.error("token 校验失败 :{}", e);
        }
        response.setStatusCode(HttpStatus.UNAUTHORIZED);//终止请求
        return response.setComplete();
    }
    /**
     * 返回错误提示信息
     * @return
     */
    private Mono<Void> writeMessage(ServerWebExchange exchange, String message) {
        Map<String, Object> map = new HashMap<>();
        map.put("code", HttpStatus.UNAUTHORIZED.value());
        map.put("errorMessage", message);
        //获取响应对象
        ServerHttpResponse response = exchange.getResponse();
        //设置状态码
        response.setStatusCode(HttpStatus.UNAUTHORIZED);
        //response.setStatusCode(HttpStatus.OK);
        //设置返回类型
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        //设置返回数据
        DataBuffer buffer = response.bufferFactory().wrap(JSON.toJSONBytes(map));
        //响应数据回浏览器
        return response.writeWith(Flux.just(buffer));
    }
}
